Pulmonary Veins

Transesophageal pulsed wave Doppler showing the timing of pulmonary venous
inflow. Normally, systolic antegrade filling of the left atrium dominates
and diastolic inflow has a shorter duration with lower peak
velocities followed by a brief flow reversal following the atrial
contraction.
This patient has an abnormal diastolic dominant inflow pattern.

OBJECTIVE: Doppler-derived flow velocity measured by transesophageal echocardiography (TEE) may overestimate pulmonary vein stenosis. We hypothesized that combining peak velocity with a stenotic flow pattern improves diagnosis compared with magnetic resonance imaging (MRI). METHODS: TEE and MRI were performed in 44 patients 19 +/- 11 months after radiofrequency catheter ablation. Pulmonary vein stenosis was defined by a peak velocity of 110 cm/s or more plus a stenotic flow pattern (turbulence and reduced flow variation) on TEE and a lumen reduction of more than 50% on MRI. RESULTS: In all, 175 pulmonary veins were studied. MRI showed 7 cases of pulmonary vein stenosis that were correctly identified by TEE. In addition, TEE criteria for pulmonary vein stenosis were met in 4 pulmonary veins that did not show obstruction on MRI. In all, 5 pulmonary veins with normal appearance on MRI had peak velocity of 110 cm/s or more with normal flow pattern. CONCLUSIONS: TEE Doppler measurements can be reliably used to detect or exclude significant pulmonary vein stenosis if the diagnosis is restricted to a combination of elevated peak velocity (> or = 110 cm/s) with turbulence and little flow variation.

BACKGROUND: Transvenous catheter ablation for the treatment of atrial fibrillation is an evolving technique. AIM: The purpose of this study was to identify subgroups of patients most likely to benefit from pulmonary vein electrical isolation. METHODS: Patients with symptomatic atrial fibrillation resistant to pharmacological therapy were studied. Mapping-guided segmental application of radio-frequency energy was used to electrically isolate the pulmonary veins in 74 patients. Ischaemic or dilated cardiomyopathy was present in 34% of patients. Atrial fibrillation had been present for a mean time (+/- standard deviation) of 6.6 +/- 6.1 years. It was paroxysmal in 53 patients (72%). RESULTS: The mean number of procedures was 1.6/patient. After 6 +/- 6 months, 73% of patients (54/74) were in sinus rhythm. Thirteen of those in sinus rhythm were using anti-arrhythmic medications (25%). Recurrence of atrial fibrillation soon after pulmonary vein isolation occurred in 50%. Patients with persistent/permanent atrial fibrillation were less likely to be in sinus rhythm at follow up (11/21 (52%) vs 43/53 (81%); P = 0.01). However, the rate of early recurrence was similar in the intermittent and the persistent/permanent groups (26/53 (49%) vs 11/21(52%), respectively; P-value not significant). Patients with persistent atrial fibrillation were more likely to experience a recurrence of atrial fibril-lation (89%; P = 0.04). No other baseline factors predicted procedural success. Cardiac tamponade occurred in two patients and moderate pulmonary vein stenosis (>50% diameter narrowing) occurred in three patients. CONCLUSIONS: Pulmonary vein isolation is an effective curative treatment for a broad group of patients with atrial fibrillation. However, the procedure is only suitable for patients with problematic atrial fibrillation resistant to other therapies because of the small risk of serious complications.

Several techniques are used for AF ablation, but no general consensus exists as to which technique is the most effective. At our center, we have developed a technique for isolating the pulmonary veins (PVs) at their antrum. The technique is guided by intracardiac echocardiography (ICE) and mapping with a circular (Lasso) catheter. Our technique was developed based on four crucial principles: 1. Precisely identifying the true border of the PV antrum. 2. Electrically isolating all of the PVs at the level of the antrum. 3. Avoiding risk of PV stenosis by ablating outside of the antrum. 4. Minimizing risk of other complications, such as perforation and stroke, by direct visualization during transseptal access and radiofrequency (RF) ablation.

INTRODUCTION: Catheter ablation has recently been used for curative treatment of atrial fibrillation. METHODS AND RESULTS: Three of 239 patients who underwent ablation close to the pulmonary vein (PV) ostia at our institute developed severe hemoptysis, dyspnea, and pneumonia as early as 1 week and as late as 6 months after the ablation. Because the patients were arrhythmia-free, the treating physician initially attributed the symptoms to new-onset pulmonary disease (e.g., bronchopulmonary neoplasm). After absent PV flow was confirmed by transesophageal echocardiography, transseptal contrast injection depicted a totally occluded PV in all three patients. Successful recanalization, even in chronically occluded Pvs, was performed in all patients. During follow-up, Doppler flow measurements by transesophageal echocardiography demonstrated restenosis in all primarily dilated PV, which led to stent implantation. CONCLUSION: PV stenosis/occlusion after catheter ablation of atrial fibrillation occurs in a subset of patients. However, because in-stent restenosis occurred in two patients after 6 to 10 weeks, final interventional strategy for PV stenosis or occlusion remains unclear. To prevent future PV stenosis or occlusion, a decrease in target temperature and energy of radiofrequency current or the use of new energy sources (ultrasound, cryothermia, microwave) seems necessary.

BACKGROUND: Pulmonary vein stenosis has recently been recognized as a complication of radiofrequency ablation for atrial fibrillation. This study evaluates the presentation of affected patients and the role of transcatheter therapy for this patient population. METHODS AND RESULTS: This study used a retrospective review of data from 19 patients (age, 51+/-13 years) with pulmonary vein stenosis who underwent catheterization and angiography between December 2000 and December 2002. Quantitative perfusion and spiral CT scans were performed for initial diagnosis and follow-up. The median duration between radiofrequency ablation and the reported onset of respiratory symptoms for 18 of 19 patients was 7.5 weeks (0.1 to 48). After the onset of symptoms, all but two patients were initially misdiagnosed with a symptoms-to-diagnosis duration of 16 weeks (2-59). At initial catheterization, 17 of 19 patients had angioplasty in 30 veins with stent placement in 5 vessels when a flap occurred. Overall vessel diameter increased from 2.6+/-1.6 to 6.6+/-2.4 mm (P<0.0001). There were 4 procedure-related adverse events but no long-term sequelae. Immediate follow-up showed improved flow to involved lung segments. At a median follow-up of 43 weeks (2-92), although repeat angioplasty for restenosis was necessary in 8 of 17 patients, 15 of 17 patients currently have no or minimal persistent symptoms. CONCLUSIONS: Pulmonary vein stenosis after radiofrequency ablation for atrial fibrillation is often misdiagnosed. Although further follow-up is necessary to determine long-term success, our data indicate better pulmonary vein flow and symptomatic improvement in the majority of patients undergoing dilation of postablation pulmonary vein stenosis.

INTRODUCTION: A recently described focal origin of atrial fibrillation, mainly inside pulmonary veins, is creating new perspectives for radiofrequency catheter ablation. However, pulmonary venous stenosis may occur with uncertain clinical consequences. This report describes a veno-occlusive syndrome secondary to left pulmonary vein stenosis after radiofrequency catheter ablation. METHODS AND RESULTS: A 36-year-old man who experienced daily episodes of atrial fibrillation that was refractory to antiarrhythmic medication, including amiodarone, was enrolled in our focal atrial fibrillation radiofrequency catheter ablation protocol. The left superior pulmonary vein was the earliest site mapped, and radiofrequency ablation was performed. Atrial fibrillation was interrupted and sinus rhythm restored after one radiofrequency pulse inside the left superior pulmonary vein. Atrial fibrillation recurred and a new procedure was performed in an attempt to isolate (26 radiofrequency pulses around the ostium) the left superior pulmonary vein. Ten days later, the patient developed chest pain and hemoptysis related to severe left superior and inferior pulmonary veins stenosis. Balloon angioplasty of both veins was followed by complete relief of symptoms after 2 months of recurrent pulmonary symptoms. The patient has been asymptomatic for 12 months, without antiarrhythmic drugs. CONCLUSION: Multiple radiofrequency pulses applied inside the pulmonary veins ostia can induce severe pulmonary venous stenosis and veno-occlusive pulmonary syndrome.

INTRODUCTION: Several reports have demonstrated that focal atrial fibrillation (AF) may arise from pulmonary veins (PVs). The purpose of this study was to investigate the safety and efficacy of using double multielectrode mapping catheters in ablation of focal AF. METHODS AND RESULTS: Forty-two patients (30 men, 12 women, age 65+/-14 years) with frequent attacks of paroxysmal AF were referred for catheter ablation. After atrial transseptal procedure, two long sheaths were put into the left atrium. Two decapolar catheters were put into the right superior PV (RSPV) and left superior PV (LSPV), or inferior PVs if necessary, guided by pulmonary venography. All the patients had spontaneous initiation of AF either during baseline (2 patients), after isoproterenol infusion (8 patients) or high-dose adenosine (2 patients), after short duration burst pacing under isoproterenol (14 patients), or after cardioversion of pacing-induced AF (16 patients). The trigger points of AF were from the LSPV (12 patients), RSPV (8 patients), and both superior PVs (19 patients). The trigger points from PVs (total 61 points) were 18 (30%) in the ostium of PVs and 43 inside the PVs (9 to 40 mm). After 6+/-3 applications of radiofrequency energy, 57 of 61 triggers were completely eliminated, and the other 4 triggers were partially eliminated. During a follow-up period of 8+/-2 months, 37 patients (88%) were free of symptomatic AF without any antiarrhythmic drugs. Twenty patients received a transesophageal echocardiogram, and 19 showed small atrial septal defects (2.8+/-1.2 mm) with trivial shunt. Fifteen defects closed spontaneously 1 month later. CONCLUSION: The technique using double multielectrode mapping catheters is a relatively safe and highly effective method for mapping and ablation of focal AF originating from PVs.

The objective of this study was to determine the utility of Doppler tissue echocardiography in the evaluation of diastolic filling and in discriminating between normal subjects and those with various stages of diastolic dysfunction. We measured myocardial velocities in 51 patients with various stages of diastolic dysfunction and in 27 normal volunteers. The discriminating power of each of the standard Doppler indexes of left ventricular filling, pulmonary venous flow, and myocardial velocities was determined with the use of Spearman rank correlation and analysis of variance F statistics. Early diastolic myocardial velocity (E(m)) was higher in normal subjects (16.0 +/- 3.8 cm/s) than in patients with either delayed relaxation (n = 15, 7.5 +/- 2.2 cm/s), pseudonormal filling (n = 26, 7.6 +/- 2.3 cm/s), or restrictive filling (n = 10, 7.4 +/- 2.4 cm/s, P

Left ventricular diastolic filling can be determined reliably by Doppler-derived mitral and pulmonary venous flow velocities. Diastolic filling abnormalities are broadly classified at their extremes to impaired relaxation and restrictive physiology with many patterns in between. An impaired relaxation pattern identifies patients with early stages of heart disease, and appropriate therapy may avert progression and functional disability. Pseudonormalization is a transitional phase between abnormal relaxation and restrictive physiology and signifies increased filling pressure and decreased compliance. In this phase, reducing preload, optimizing afterload, and treating the underlying disease are clinically helpful. A restrictive physiology pattern identifies advanced, usually symptomatic disease with a poor prognosis. Therapeutic intervention is directed toward normalizing loading conditions and improving the restrictive filling pattern, although this may not be feasible in certain heart diseases. Finally, many patients have left ventricular filling patterns that appear indeterminate or mixed. In these cases, clinical information, left atrial and left ventricular size, pulmonary venous flow velocity, and alteration of preload help assess diastolic function and estimate diastolic filling pressures.

Pulmonary vein stenosis was diagnosed by transesophageal echocardiography in five patients who underwent the study for different clinical indications. Stenosis was encountered in the right upper pulmonary vein in two patients, the right lower pulmonary vein in two patients, and at the confluence of the left pulmonary veins in one patient. In only one patient was the diagnosis suspected on transthoracic echocardiography. Contralateral normal veins from the same patient served as the control. Vessel diameter and peak flow velocity were measured and compared. The diameter of the stenosed veins ranged from 0.3 to 0.8 cm (mean 0.4 +/- 0.09 cm [SEM]), whereas for normal veins the diameter was 0.9 to 1.2 cm (mean 1.0 +/- 0.05 cm [SEM]; p < 0.001). Peak flow velocity in the stenosed veins ranged from 1.1 to 1.6 m/sec (mean 1.4 +/- 0.1 m/sec [SEM]), whereas in normal veins peak flow velocity ranged from 0.4 to 0.7 m/sec (mean 0.6 +/- 0.04 m/sec [SEM]; p < 0.001). There was a strong negative correlation between vessel diameter and peak flow velocity (R = 0.89; p < 0.001). Peak flow velocity of 0.8 m/sec appears to provide the best separation between normal and stenosed pulmonary veins. We conclude that pulmonary vein stenosis is associated with increased flow velocity and turbulence and deformity of the flow signal. Transesophageal echocardiography is a powerful tool in the study of pulmonary vein stenosis.

Two patients with a malignancy involving the lungs and spontaneous systemic embolization in whom transesophageal echocardiography detected masses consistent with tumor invading the pulmonary veins are reported. In the first patient, tumor embolization resulted in acute aortic obstruction. Transesophageal echocardiography revealed tumor present in the pulmonary veins that extended into the left atrium. This was confirmed by magnetic resonance imaging. The second patient had a stroke. Transesophageal echocardiography demonstrated a mass in the right pulmonary vein in this patient as well. In patients with pulmonary malignancy who have a systemic embolic event, tumor emboli from the pulmonary vein should be included in the differential diagnosis of possible causes of the event. Transesophageal echocardiography is a valuable tool for diagnosis of tumor involvement of the pulmonary veins in such patients.

Because analysis of pulmonary venous flow (PVF) will be extensively used in comprehensive Doppler assessment of left ventricular diastolic function, this study was designed to (1) evaluate the feasibility of PVF measurement in 116 consecutive patients with various cardiac abnormalities by using precordial pulsed Doppler echocardiography; (2) Estimate mean pulmonary capillary pressure (MPCP) and left ventricular end-diastolic pressure (LVEDP) from Doppler variables of PVF and mitral inflow; and (3) evaluate the influence of clinical and hemodynamic variables on PVF Doppler patterns. We adequately recorded anterograde PVF in 96 (82.7%) patients and retrograde PVF in 45 (38.7%) patients. The strongest correlation between MPCP and Doppler variables of PVF was found with systolic fraction (the systolic velocity time integral expressed as a fraction of total anterograde PVF) (r = -0.88; p < 0.001). Age influenced this relation, with progressive increase of the systolic fraction in older patients. A good correlation (r = 0.72; p < 0.001) was found between LVEDP and the difference in duration of the reversal PVF and the mitral a wave. In conclusion, (1) PVF can be recorded adequately in most patients with precordial Doppler echocardiography; (2) left ventricular diastolic pressures can be estimated reliably by precordial Doppler echocardiography; and (3) the clinical meaning of Doppler-derived indexes of left ventricular diastolic performance is age-related.

Pulmonary venous flow patterns have been used to assess severity of mitral regurgitation; however, the issue of which pulmonary veins to sample has not been determined. We performed pulsed wave Doppler transesophageal echocardiography of both the left and right upper pulmonary veins in 80 patients who had mitral regurgitation determined by independent transesophageal echocardiography color flow mapping. Pulmonary venous flow patterns, peak systolic and diastolic flow, and the presence of reversed systolic flow were compared between the left and right pulmonary veins for each grade of mitral regurgitation. Flow patterns were discordant in 20 (25%) of the 80 patients. Of the 43 patients with 4+ mitral regurgitation, there was discordant flow in 16 (37%) of the patients with mainly reversed systolic flow in the right upper vein, while there was blunted or normal systolic flow in the left upper vein. Of the 16 patients with discordant flows, 14 had eccentric jets, mainly anteromedial jets. We conclude that if discordant flow can occur in 25% of patients with mitral regurgitation and in 37% of patients with 4+ mitral regurgitation, then both pulmonary veins must be evaluated when assessing the severity of mitral regurgitation with pulsed wave Doppler transesophageal echocardiography.

OBJECTIVES. The purpose of this study was to test the utility of measuring respiratory variation in pulmonary venous flow by transesophageal echocardiography. BACKGROUND. Respiratory variation of atrioventricular and central venous flow velocities by Doppler echocardiography has been used to differentiate constrictive pericarditis from restrictive cardiomyopathy. METHODS. We performed pulsed wave Doppler transesophageal echocardiography of the left or right pulmonary veins in 31 patients with diastolic dysfunction. Fourteen patients had constrictive pericarditis, and 17 had restrictive cardiomyopathy. We measured the pulmonary venous peak systolic and diastolic flow velocities and the systolic/diastolic flow ratio with transesophageal echocardiography during expiration and inspiration. The percent change in Doppler flow velocity from expiration to inspiration (%E) was calculated. RESULTS. Pulmonary venous peak systolic flow in both inspiration and expiration was greater in constrictive pericarditis than in restrictive cardiomyopathy. The %E for peak systolic flow tended to be higher in constrictive pericarditis (19% vs. 10%, p = 0.09). In contrast, pulmonary venous peak diastolic flow during inspiration was lower in constrictive pericarditis than in restrictive cardiomyopathy. The %E for peak diastolic flow was larger in constrictive pericarditis (29% vs. 16%, p = 0.008). The pulmonary venous systolic/diastolic flow ratio was greater in constrictive pericarditis in both inspiration and expiration. The combination of pulmonary venous systolic/diastolic flow ratio > or = 0.65 in inspiration and a %E for peak diastolic flow > or = 40% correctly classified 86% of patients with constrictive pericarditis. CONCLUSIONS. The relatively larger pulmonary venous systolic/diastolic flow ratio and greater respiratory variation in pulmonary venous systolic, and especially diastolic, flow velocities by transesophageal echocardiography can be useful signs in distinguishing constrictive pericarditis from restrictive cardiomyopathy.

The effect of mitral regurgitation on pulmonary venous flow velocity was studied in 66 patients undergoing transesophageal echocardiography. Nine patients were studied intraoperatively before and after surgery, so that 75 pulmonary venous flow tracings were analyzed. Fifty-four patients had no significant (0 to 1+) mitral regurgitation and 21 had significant (2 to 3+) mitral regurgitation. Comparison of both groups revealed significant differences in the pulmonary venous flow pattern. In patients with no significant mitral regurgitation, the peak systolic velocity was higher (55 +/- 16 vs. -4 +/- 16 cm/s; p less than 0.0001) and the peak diastolic velocity was lower (43 +/- 13 vs. 59 +/- 17 cm/s; p less than 0.01) when compared with values in patients with significant mitral regurgitation. Consequently, the peak systolic/diastolic velocity ratio was significantly higher in the patients without significant mitral regurgitation (1.4 +/- 0.5 vs. 0.4 +/- 1.3; p less than 0.0001). The same trend was noted with respect to the systolic and diastolic velocity integrals. As the degree of mitral regurgitation increased, the peak diastolic velocity and diastolic velocity integral increased, whereas the peak systolic velocity and systolic velocity integral decreased. In patients with severe mitral regurgitation, the systolic flow became reversed (retrograde). The sensitivity of reversed systolic flow for severe mitral regurgitation was 90% (9 of 10), the specificity was 100% (65 of 65), the positive predictive value was 100% (9 of 9), the negative predictive value was 98% (65 of 66) and the predictive accuracy was 99% (74 of 75).

Pulmonary venous flow as assessed by Doppler echocardiography is a current topic of investigation. Pulmonary venous flow has been used recently as part of a comprehensive assessment of left ventricular diastolic filling dynamics in restrictive myocardial diseases and constrictive pericarditis. Abnormalities of flow have been described in dilated cardiomyopathy, congenital heart disease, and arrhythmias. With the advent of transesophageal echocardiography, pulmonary venous flow can be readily obtained in all patients by pulsed-wave Doppler echocardiography. Recently, it has been used to assess the severity of mitral regurgitation and to estimate mean left atrial pressure. This article emphasizes the utility, physiology, and technique of measuring pulmonary venous flow with Doppler echocardiography in health and in disease.

Pulmonary venous flow varies with different cardiac conditions. Flow patterns in response to mitral regurgitation have not been well studied, but flows may vary enough to differentiate among different grades of regurgitation. Accordingly, pulmonary venous flow velocities were recorded in 50 consecutive patients referred for outpatient (n = 26) or intraoperative (mitral valve repair; n = 24) echocardiographic examination for mitral regurgitation. Recordings were made of right and left upper pulmonary veins with pulsed wave Doppler transesophageal echocardiography. Mitral regurgitation was graded from 1+ to 4+ by an independent observer using transesophageal color flow mapping. The results of cardiac catheterization performed 5 weeks earlier in 43 of the patients were also graded for mitral regurgitation by an independent observer. Pulmonary venous flow patterns, the presence of reversed systolic flow and peak systolic and diastolic flow velocities were compared with the severity of mitral regurgitation indicated by each technique. Of the 28 patients with 4+ regurgitation by transesophageal color flow mapping, 26 (93%) had reversed systolic flow. The sensitivity of reversed systolic flow in detecting 4+ mitral regurgitation by transesophageal color flow mapping was 93% and the specificity was 100%. The sensitivity and specificity of reversed systolic flow in detecting 4+ mitral regurgitation by cardiac catheterization were 86% and 81%, respectively. Discordant flows were observed in 9 (24%) of 38 patients; the left vein usually showed blunted systolic flow and the right showed reversed systolic flow. In 22 intraoperative patients, there was "normalization" of pulmonary venous systolic flow after mitral valve repair in the postcardiopulmonary bypass study compared with the prebypass study after the mitral regurgitant leak was corrected.(ABSTRACT TRUNCATED AT 250 WORDS)

We have previously shown that the systolic and diastolic pulmonary venous flow (PVF) distribution is predictive of left atrial pressure. This study was designed to define the confounding influences of left atrial expansion, descent of the mitral anulus, and left ventricular contractile function on that relationship; to define normal PVF patterns; and to document the interaction of PVF with mitral inflow. Therefore we studied 27 consecutive intraoperative patients with coronary artery disease (22 men and 5 women, ages 35 to 78 years) using transesophageal echocardiography. A group of 12 normal subjects served as a control. Doppler and two-dimensional echocardiographic parameters were obtained simultaneously with monitoring pulmonary capillary wedge pressure (PCWP). We found that neither left atrial expansion nor the descent of the mitral anulus influenced the relationship between PVF and PCWP, but that left ventricular fractional shortening confounded this relationship. In normal subjects PVF was dominant in systole, whereas PVF in patients with elevated PCWP was dominant in diastole (systolic fraction of 68 +/- 6% [SD] in normals versus 42 +/- 15% in patients with PCWP greater than or equal to 15 mm Hg). PVF velocities interacted with transmitral flow velocities. Peak early diastolic mitral inflow velocities increased linearly with peak early diastolic PVF velocities (r = 0.62). We conclude that systolic and diastolic PVF distribution is mainly determined by the level of PCWP and to a lesser extent by left ventricular contraction, but not by left atrial expansion or by mitral anulus descent. Transesophageal pulsed Doppler echocardiography of PVF provides useful clinical information about the level of PCWP in intraoperative patients with coronary artery disease.

The records of 23 infants who underwent surgical repair of isolated totally anomalous pulmonary venous connection were reviewed to assess the accuracy of pre- and postoperative echocardiographic diagnoses. Preoperative echocardiographic diagnoses were accurate in 22 of 23 patients, including the sites of connection of the individual pulmonary veins. Cardiac catheterization in 13 patients confirmed the echocardiographic findings. Analysis of multiple pre- and postoperative variables revealed no statistically significant difference between the infants with and without catheterization, although there was a tendency toward a higher mortality rate in the catheterized group. Postoperative echocardiographic examination revealed obstruction to pulmonary venous return in 7 of 19 patients. Catheterization confirmed the echocardiographic findings, localizing the obstruction in one patient. The size of the venoatrial anastomosis was measured on postoperative echocardiograms performed on 14 patients. The cross-sectional area of the anastomosis was less than 0.3 cm2/m2 of body surface area in the four patients with obstruction of the anastomosis, and greater than 0.95 cm2/m2 in all long-term survivors examined. Two-dimensional echocardiography with pulsed Doppler examination and Doppler color flow mapping is an excellent means of diagnosing totally anomalous pulmonary venous connection. The connections of the individual pulmonary veins can be identified in nearly all cases. Surgical repair can usually be undertaken on the basis of echocardiographic diagnosis alone. Echocardiography also provides an extremely accurate method of evaluating surgical repair and of identifying and localizing postoperative obstruction to pulmonary venous return.